Connector for electrical conductors



July 19, 1949. B. PAULES CONNECTOR FOR ELECTRICAL CONDUCTORS Filed Aug. 30, 1946 ATTo Y INVENTOR LEMON B. PAULES Patented July 19, 1949 CONNECTOR FOR ELECTRICAL CONDUCTORS Lemon B. Paules, Harrisburg, Pa., assignor to Aircraft-Marine Products, Inc., Harrisburg, Pa., a corporation of New Jersey Application August 30, 1946, Serial No. 694,111

2 Claims.

This invention relates to connectors for electrical conductors and more particularly it pertains to connectors of the type which are intended to be connected to an electrical conductor by a crimping operation.

Of the connectors now on the market, which are intended to be crimped onto electrical conductors to effect permanent conductive connections thereto, substantially all require stripping of the conductor end to provide the contact surface for effecting a conductive connection. However, in a, co-pending application of William F. Broske, Serial No. 574,458 filed January 25, 1945 is shown a connector which is so constructed and arranged that it may be crimped directly onto the end portion of an insulated electrical conductor without the necessity of stripping insulation from the conductor. In the connector shown and described in said co-pending application the conductive connection between the terminal contact portion of the connector and to which it is attached is made by a metal spear centrally arranged within a ferrule; and in the example shown this spear serves also as a rivet to connect it directly with the terminal contact portion of the connector and both to the ferrule. This spear stabbing into the conductor end as it is inserted into the ferrule makes contact engagement with the stranded wire conductor without the necessity for stripping insulation therefrom; and when the ferrule is subsequently crimped, the stranded wire and the spear are compressed into conductive relation and the spear gripped so that its head can no longer be withdrawn through the crim ped area.

In the connector shown in the co-pending application, the three elements, a thimble-like ferrule, a contact tongue and a spear, have to be separately made and assembled, which results in relatively high cost. Moreover, the use of a closed end ferrule, while it is advantageous in certain respects, has the disadvantage that it does not permit visual inspection of the extent of insertion of the conductor into the ferrule.

The present invention is an improvement on said connector of the co-pending application.

One of the objects of the present invention is to provide a connector which may be crimped directly onto the end of an insulated electrical conductor without the necessity of stripp n in- Another object of the invention is to provide v an electrical connector adapted to be connected and secured to an unstripped insulated conductor by crimping thereon. To these ends, I have provided a novel connector comprising a term'inal contact portion, an open-end ferrule for the reception of the unstripped end of the insulated conductor and a conductive prong integral with the ferrule and estending in the ferrule approximately along its axis, whereby to be stabbed into conductive contact with the stranded wire conductor andthe ferrule being adapted for crimping upon said unstripped insulated conductor end and, when thus crimped, to hold the conductor in permanent conductive connection therewith, and secure mechanical engagement.

An important feature in one of the preferred embodiments of the invention is the provision of a spear or prong integral with the connector and of sufilcient length so that the spear proper may be offset inwardly toward the axis of the conductor which is to be connected in the ferrule, with its stabbing end directed toward the conductorreceiving end of the ferrule, thus bringing it into position to insure a good conductive contact with I the wires of the conductor when the connector is placed on the upstripped end thereof.

Other objects, important features and advantages of the invention, to which attention has specifically been directed hereinabove, will appear hereinafter when the following description and claims are considered in connection with the accompanying drawings, in which Figure 1 is a plan view of a blank stamped from sheet metal preparatory to forming one embodiment of the novel connector of the present invention;

Figure 2 is an end view of the same blank after the initial ofisetting and re-dlrecting of the spear portion has been performed thereon;

I Figure 3 shows in plan view the same structure after the ferrule-forming wings of the blank have been rolled up to shape the finished ferrule;

Figure 4 shows this embodiment of the invention crimped upon the unstripped end of an electrical conductor;

Figure 5 is a view in horizontal axial section of a modified form of the invention in which the spear is stamped up from the neck which connects the terminal contact with the ferrule and includes some of the material which would normally be cut from the terminal contact to form the binding post opening therein;

Figure 6 is a vertical axial section on line 6-6 of Figure 5;

Figure 7 shows still another modification in which the spear part of the connector is stamped up out of the ferrule part of the blank and is initially pointed in the proper conductor stabbing direction; and

Figure 8 is a longitudinal section 8-8 of Figure '7.

In the form of the invention shown in Figures 1-4 inclusive, the initial blank is cut from a sheet of ductile conductive metal, such as pure copper, soft brass, or even mild steel, upon which power tools can be used for crimping. The blank is shown as comprising a rounded terminal contact portion 2. The form of this portion is optional and not a part of the invention: it is shown here as having a central opening 4 therein, of a shape and size to fit over a binding post or other terminal with which the connector is to be used, and a neck 6 which connects the terminal contact portion 2 with the part of the blank from which the ferrule is to be formed. The ferrule art of the blank comprises laterally extending ears 8 and 8 which, when rolled up into the cylindrical form shown in Figures 3 and 4, form with the intermediate body portion a cylindrical ferrule 10 of an internal diameter adapted to receive the unstripped end of an insulated stranded wire conductor of the particular size for which the connector is made.

In the embodiment of the invention shown in Figures 1-4, inclusive, the spear part of the connector is shown in the original blank in Figure 1 as being constituted byan integral extension l2 of the left hand margin of the ear 8, this extension having an approximately pointed end which, in the stamping operation, has been tapered to a sharp edge or point. This spear I2 is pointed in the opposite direction :from the desired direction in the finishing connector, but the extension is of sufilcient length so that, as shown in Figure 2, it will provide for a sufficient bodily offsetting of the main part of the spear from the body wall of the ferrule, as it is turned to point in the proper direction, so that the spear, in the finished connector, as shown in Figures 3 and 4, is located substantially at the axis of the ferrule when the parts are rolled up into the shape shown in Figure 3. The meeting edges of the ears 8 and 8' may be brazed together, if desired, or, as is sometimes done in the use of connectors of this type, a sleeve, not shown, may be fitted over the ferrule part of the connector.

As shown in Figure 4, when the connector shown in Figure 3 is pushed over the unstripped end of an insulated conductor, the spear I2 is stabbed into the central conductor and thus comes into contact with the conductor wires. When the connector is crimped onto the wire, the strands of the central conductor are compressed into secure engagement and good electrical contact with the spear l2.

taken on line In the form of the invention shown in Figures 5 and 6, the spear 12a, instead of being formed, as is the spear .l2 of Figure l, as an integral extension of the marginal edge of one of the ears of the blank which are to form the ferrule, is stamped out of the neck and terminal contact portions of the connector, 2. part of the spear being constituted by a :part of the material out out to form the opening 4 in the terminal contact portion 2 of the connector and the remaining part of the spear, including a part of the offsetting connection, being cut out of the neck part 6 of the original blank. This spear l2a, like the spear I2 of the first-described embodiment will be seen to have been pointed in the wrong direction in the original blank and then to have been turned over and offset to the center of the finished ferrule, as shown particularly in Figure 6.

In Figure '7 is shown stillanother modification in which the spear, instead of being formed in the blank with its stabbing end pointed in the wrong direction, as shown in Figures 1-6 inclusive, is stamped up out of the body of the ferrule itself, the spear 12b, shown in Figure 7, having its stabbing end originally pointed in the proper direction for use. As also shown in Figure '7, the blank length of the spear l2b is suflicient to provide for its offsetting, as shown in Figure 8, to bring the spear proper to the center of the ferrule. This is inferior to the examples shown in Figures 1-6; in that it necessitates slitting the ferrule, which would impair the strength of engagement when the ferrule is crimped onto a wire. This may be substantially corrected by fitting a sleeve over the ferrule, or the ferrule may be given a final forming operation, by which the slit is closed, at the same time providing a slightly reduced diameter with a bell-mouth to facilitate insertion of the wire. The abutting edges of the ears and the edges at the closed slit are advantageously brazed for cirumferentialv strength.

It will be seen that when the ferrules of the connector shown in Figures 5-8 are crimped into permanent connection with the unstripped end of the conductor having the spear l2 etc., located therein, a good electrically conductive connection will be established from the conductive wires at the center of the conductor through the spear l2 etc., to the terminal contact portion 2 of the connector.

While no particular crimp is essential to the presentinvention, it is important to use a crimp of the type which forms the metal of the ferrule so that the stranded connector is compacted, consolidated and held under compression. Suitable crimps for this purpose are described and claimed, for example, in Patent No. 2,359,084.

What I claim is:

1. A blank of ductile sheet metal for forming a terminal comprising a substantially rectilinear ferrule-forming portion having an integral contact-forming portion extending from one of its sides and an integral spear portion extending from the same side of said ferrule-forming portion, the axis of said spear portion being spaced from the axis of said connector portion a distance substantially equal to one-half the length of said side of said ferrule-forming portion.

2. An electrical connector comprising a hollow, imperforate cylindrical ferrule open at both ends and having a seam, a spear integral with said ferrule and extending inwardly at one end of the ferrule to the long axis of the ferrule and then extending within the ferrule along the long axis torted.

I '5 7 thereof and ending in a sharp point within the LEMON B. ,PAULES.

REFERENCES CITED The following references are of record in the flle of this patent:

5 UNITED STATES PATENTS Number Name Date 2,379,567 Buchanan July 3, 1945 2,382,292 Carlson Aug. 14, 1945 FOREIGN PATENTS Number Country Date 596,408 France Aug. 8, 1925 France Jan. 19, 1935 

